The invention relates to the detection, diagnosis and treatment of skin cancer as well as other diseases and cosmetic conditions of the visible human.
Half of all new cancers are skin cancers. About 1.3 million new cases of skin cancer will be diagnosed in the United States each year. About 80 percent of the new skin cancer cases will be basal cell carcinoma, 16 percent are squamous cell carcinoma, and 4 percent are melanoma.
Both basal cell carcinoma and squamous cell carcinoma have a better than 95 percent cure rate if detected and treated early. Squamous cell carcinoma of the skin accounts for about 2.3 thousand deaths annually.
The incidence of melanoma has more than tripled among Caucasians between 1980 and 2000. There will be about 47,700 new cases of melanoma in 2000. At current rates, one in 74 Caucasian Americans will develop melanoma. With that statistic, one person dies of melanoma every hour. This year, approximately 7,700 deaths will be attributed to melanoma in the ratio of 4,800 men and 2,900 women. Older Caucasian males have the highest mortality rates from melanoma. In women under the age of 30, melanoma is more prevalent than breast cancer. All of these cancers are associated with sun exposure with the majority occurring after age 50. Furthermore, the incidence rates for all skin cancers are increasing with movement of white populations south to sunnier climates and the greater numbers of individuals living into their 80s. With the “baby boomer” generation currently in their late 50s, the medical community is faced with an explosive skin cancer epidemic.
There is a need for a practical device that allows for the rapid screening of individuals for skin cancer and other maladies of the skin in early stages of development.
Currently, clinical diagnosis of skin disease is generally accomplished by visual inspection under white light illumination. In this process, the reflectance light of a skin lesion is examined. Visual diagnosis alone may not be particularly accurate for early detection of skin cancer since many skin conditions have a similar appearance under white light. Therefore, when a suspect lesion is identified by visual examination, a biopsy is often performed for a definitive diagnosis. Not only is it crucial to diagnose skin pre-cancer or skin cancer at an early stage when it is curable, but it is also important to improve the clinical diagnosis of suspected skin lesions so as to avoid unnecessary skin biopsies.
Several approaches have been tried to improve skin cancer diagnosis. Digital processing of reflectance images has been extensively investigated recently and has been found in melanoma to be more accurate than specialist diagnostic accuracy. An alternative approach is ultraviolet (UV), infrared (IR) or polarized light photography that extends visual perception of a physician to the UV, IR or polarized light reflectance patterns. A further alternative approach that is already in widespread medical use involves illuminating the skin with a “Wood's lamp” which consists of a mercury discharge lamp associated with a filter that transmits UVA light with a 365 nanometer peak while absorbing visible light. When this device is used to assist in skin diagnosis, the eye serves as both the detector and the long pass filter. The eye is not sensitive to UV light, but is sensitive to visible fluorescence light. When the “Wood's lamp” is used in a darkened room, the physician sees an image of a fluorescing disease site. The “Wood's lamp” is useful for the diagnosis of some skin conditions such as tinea capitis, tinea versicolor, erythrasma, and some pseudomonas infections, as well as aiding in the detection and diagnosis of hypopigmented skin. It is of no value in conditions where the fluorescence is not in the visible spectrum. These techniques depend on lighting and sensor techniques and may be incorporated into the total immersion photography system.